Chitosan as a carbonation catalyst in lime mortars

Abstract

The investigation evaluates the influence of unmodified chitosan on the carbonation behavior of aerial lime mortars, determining the main properties in hardened state. The work was developed experimentally, starting from lime pastes elaborated according to European Standards. Initially, different contents of chitosan were dissolved in the mixing water, keeping constant the quantity of aerial lime and water, according to the consistency standardized by the type of lime. The samples cured for 4 days in an oven at 30 °C, were subjected to a carbonation process. The carbonation conditions established for the lime samples, with and without chitosan, were in all cases the same. It was observed that the chitosan content positively influences the kinetic reactions of lime with CO2, modifying its mineralogical, macro and microstructural properties and improving its mechanical behavior.